Method to separate an emulsion in a liquid lens

Abstract

Embodiments generally relate to systems and methods for separating an emulsion in a cavity of a device such as a liquid lens device. In one embodiment, the method comprises at least one of: applying a bias voltage to electrodes in the device, causing at least one of droplet migration, flattening of large droplets, and reduced droplet surface tension; applying an oscillating actuation voltage waveform comprising an actuation frequency to the electrodes, such that fluid pumping and turbulence is created within the device cavity; and applying an oscillating excitation voltage waveform comprising an excitation frequency to the electrodes, such that the varying electric field created by the oscillating voltage causes small droplets of the first liquid to coalesce.

The invention claimed is: 
     
       1. A method for separating an emulsion comprising droplets of a first liquid suspended in a second liquid within a cavity of a liquid lens device, the method comprising at least one of:
 applying a bias voltage to electrodes in the liquid lens device, causing at least one of droplet migration, flattening of large droplets, or reduced droplet surface tension; 
 applying an oscillating actuation voltage waveform comprising an actuation frequency to the electrodes, such that fluid pumping and turbulence is created within the liquid lens cavity; or 
 applying an oscillating excitation voltage waveform comprising an excitation frequency to the electrodes, such that a varying electric field created by the oscillating excitation voltage causes small droplets of the first liquid to coalesce. 
 
     
     
       2. The method of  claim 1  comprising applying the bias voltage to the electrodes to encourage migration of the first liquid toward one side of the liquid lens cavity and migration of the second liquid toward an oppositely situated side of the liquid lens cavity. 
     
     
       3. The method of  claim 1  comprising applying the oscillating actuation voltage waveform and applying the oscillating excitation voltage waveform, wherein the actuation frequency is lower than the excitation frequency. 
     
     
       4. The method of  claim 3  wherein the ratio of excitation frequency to actuation frequency is in the range of 2 to 100. 
     
     
       5. The method of  claim 3  wherein the actuation frequency is 50 Hz and the excitation frequency is 100 Hz. 
     
     
       6. The method of  claim 1  comprising applying the oscillating excitation voltage waveform, wherein the oscillating excitation voltage waveform comprises at least one of a sine waveform, a square waveform, a triangle waveform, or a saw-tooth waveform. 
     
     
       7. The method of  claim 1  comprising applying the oscillating excitation voltage waveform, wherein the oscillating excitation voltage waveform comprises a swept sine function. 
     
     
       8. The method of  claim 1  comprising applying the oscillating actuation voltage waveform, wherein the oscillating actuation voltage waveform comprises first and second waveforms, and wherein applying the oscillating actuation voltage waveform comprises applying the first waveform to one electrode in the liquid lens device and applying the second waveform to an oppositely situated electrode in the liquid lens device, so that a meniscus present between the first and second liquids experiences a tilting actuation. 
     
     
       9. The method of  claim 8  wherein the first and second waveforms are applied in a rotational manner around an axis of symmetry through the liquid lens cavity such that the tilted meniscus rotates correspondingly around the axis in a sweeping action. 
     
     
       10. The method of  claim 1  comprising applying the oscillating excitation voltage waveform, wherein the oscillating excitation voltage waveform comprises a periodic dwell time at a constant predetermined voltage. 
     
     
       11. The method of  claim 10  wherein the dwell time occurs at intervals corresponding to 5 cycles of the actuation frequency. 
     
     
       12. The method of  claim 1  wherein the applying the at least one of the bias voltage, the oscillating actuation voltage waveform, or the oscillating excitation waveform occurs in response to a signal received from an acceleration sensor indicating an anticipated shock event likely to be experienced by the liquid lens device. 
     
     
       13. A method for separating an emulsion comprising droplets of a first liquid suspended in a second liquid within a cavity of a Lab-On-Chip device, the method comprising at least one of:
 applying a bias voltage to electrodes in the Lab-On-Chip device, such that large droplets of the first liquid experience flattening and reduced surface tension; 
 applying an oscillating actuation voltage waveform comprising an actuation frequency to the electrodes, such that fluid pumping and turbulence is created within the cavity; or 
 applying an oscillating excitation voltage waveform comprising an excitation frequency to the electrodes, such that a varying electric field created by the oscillating voltage causes small droplets of the first liquid to coalesce.